Crew on the International Space Station will no longer have to hide from a possible collision with some space debris, after NASA flight controllers decided it posed no threat to the station.

The ISS 'nauts had been told to take shelter in their Soyuz spacecraft in case the debris from the Fengyun 1C, a Chinese satellite, hit the station.

Usually if there's a danger of something hitting the ISS, the crew manoeuvre it out of the way, but this time they were too busy sorting out the return journey of the Expedition 29 astronauts to do that.

NASA initially predicted that the space junk would come within 850 metres of the station. If tracking had continued to show its closest approach within a predetermined distance around the ISS, the crew would have had to take precautions, including closing the hatches between station modules and getting into their Soyuz.

Space junk is a familiar issue to the ISS and crew members have had to deal with rogue bits and pieces many times throughout the years.

In April this year, two supply ships docked with the station gave it a shove so that it could evade a cloud of shrapnel created when a military satellite crashed into an Iridium comsat some years before.

And in 2009, the crew aboard the station did take shelter in a Soyuz spacecraft when a discarded mechanism used to boost a satellite into higher orbit came close to hitting it, but in the end it passed without incident.

According to NASA, more than 500,000 pieces of debris are tracked as they orbit the Earth and they all travel at speeds of up to 17,500 mph, "fast enough for a relatively small piece of orbital debris to damage a satellite or a spacecraft".

"Even tiny paint flecks can damage a spacecraft when traveling at these velocities. In fact a number of space shuttle windows have been replaced because of damage caused by material that was analyzed and shown to be paint flecks," NASA has said. ®